Hillsboro police are searching for suspects in a gang-related assault that sent a 38-year-old man to the intensive care unit at a local hospital Sunday morning.

About 9 a.m. Sunday, officers responded to a report of an assault with a baseball bat that occurred near the intersection of Southeast 10th Avenue and Maple Street, said Lt. Mike Rouches, a Hillsboro police spokesman. Police found a man, whom they identified as Armando Santoya, of Hillsboro, unconscious on the sidewalk. Officers called for paramedics and Santoya was rushed to OHSU Hospital in Portland, where he remained unconscious Monday morning, Rouches said.

His current condition was not immediately available.

Police, Rouches said, learned from a witness that Santoya was walking east on Maple Street and talking on his cellphone, when a medium-sized, gold-colored sedan passed by west on Maple. Rouches said the witness, who was also walking in the area, saw the vehicle stop in the middle of the street about 50 feet from Santoya.

A man with a black, aluminum baseball bat jumped out of the right rear seat, Rouches said, and ran up behind Santoya. The two briefly exchanged words, but the witness couldn't hear what was said.

The man cocked the bat over his head and struck Santoya once in the back of his head, Rouches said. Santoya fell to the ground, and didn't move. He suffered a fractured skull, Rouches said, and bruised brain.

The man reportedly ran back to the car, which took off west on Maple Street, and the witness called 9-1-1.

The man is described as about 18 years old and 5 feet 7 inches tall with a medium build and shaved head. At the time of the assault, he was wearing a white, long-sleeved T-shirt; black basketball shorts; white, knee-length socks and black sandals, Rouches said.

The black baseball bat, Rouches said, may have silver stripes on it. The witness, Rouches said, said there were possibly three other suspects – in their early 20s – inside the car. The other suspects, Rouches said, remained in the car during the assault. The witness reportedly had not seen the suspects before.

Police searched the area for the suspects, but could not locate them. Hillsboro detectives are investigating and have also forwarded the case to the county's Interagency Gang Enforcement Team.

Anyone with information is asked to call Hillsboro police at 503-681-6175.